Organic light-emitting display apparatus

ABSTRACT

An organic light-emitting display apparatus includes a thin-film transistor on a substrate, a planarization layer on the thin-film transistor, and a pixel-defining spacer on the planarization layer. The pixel-defining spacer defines a pixel area between two pixels that are adjacent in a first direction.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

This application claims the benefit of Korean Patent Application No.10-2015-0015577, filed on Jan. 30, 2015, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

1. Field

One or more embodiments relate to organic light-emitting displayapparatuses.

2. Description of the Related Technology

Organic light-emitting display apparatuses are self-emission displayapparatuses which have an organic light-emitting device including a holeinjection electrode, an electron injection electrode, and an organicemission layer formed between the hole injection electrode and theelectron injection electrode, and emit light when excitons generated bycombining holes injected from the hole injection electrode and electronsinjected from the electron injection electrode inside the organicemission layer drop from an excited state to a ground state.

As organic light-emitting display apparatuses have self-emittingcharacteristics, they do not require a separate light source. Thus, theorganic light-emitting display apparatuses may be driven at a lowvoltage, be formed to be lightweight and thin, and have high-qualitycharacteristics such as wide view angles, good contrast, and quickresponse times. Accordingly, such apparatuses have drawn attention asnext-generation display apparatuses.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One or more embodiments include an organic light-emitting displayapparatus.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, an organic light-emitting displayapparatus includes: a thin-film transistor on a substrate; aplanarization layer on the thin-film transistor; and a pixel-definingspacer on the planarization layer, wherein the pixel-defining spacerdefines a pixel area and is between two pixels adjacent in a firstdirection.

The two adjacent pixels may be blue.

Among the blue pixels in the pixel area, a first gap between first twoneighboring blue pixels and a second gap between second two neighboringblue pixels may be alternately and regularly formed, the first gap maybe different from the second gap, and the pixel-defining spacer may beformed in a region in which a gap between two neighboring blue pixels iswide.

The pixel-defining spacer may be between two green pixels adjacent in asecond direction and between two red pixels adjacent in the seconddirection, wherein the second direction is perpendicular to the firstdirection.

The pixel-defining spacer may be rectangular shaped.

The pixel-defining spacer may be lozenge shaped.

The pixel-defining spacer may be spaced apart from the blue pixels by atleast about 8 μm.

The pixel-defining spacer may be spaced apart from green pixels or redpixels by at least about 9.2 μm.

The pixel-defining spacer may be hexagonal shaped.

The pixel-defining spacer may be spaced apart from the blue pixels by atleast 9 μm.

The pixel-defining spacer may be spaced apart from green pixels or redpixels by at least about 9.6 μm.

Blue pixels in the pixel area may be formed such that two differentgaps, each gap between two neighboring blue pixels, are alternately andregularly formed, and the pixel-defining spacer may be formed indifferent shapes in a region in which a gap between a first twoneighboring blue pixels is narrow and in a region in which a gap betweena second two neighboring blue pixels is wide.

The pixel-defining spacer may be trapezoidal shaped in the region inwhich a gap between two neighboring blue pixels is narrow.

The top of the trapezoidal shaped pixel-defining spacer may be locatedbetween the two blue pixels, and the bottom of the trapezoidal shapedpixel-defining spacer may be located between adjacent green and redpixels.

The pixel-defining spacer may be quadrilateral shaped in the region inwhich a gap between two neighboring blue pixels is wide.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 illustrates a cross-sectional view of an organic light-emittingdisplay apparatus according to an embodiment;

FIG. 2 illustrates a top view of an organic light-emitting displayapparatus according to an embodiment;

FIG. 3 illustrates a top view of an organic light-emitting displayapparatus according to another embodiment;

FIG. 4 illustrates a top view of an organic light-emitting displayapparatus according to another embodiment;

FIG. 5 illustrates a top view of an organic light-emitting displayapparatus according to another embodiment.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals generally refer to like elements throughout. In this regard,the embodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description.

It will be understood that although the terms “first”, “second”, and thelike may be used herein to describe various components, these componentsshould not be limited by these terms. These components are only used todistinguish one component from another.

As used herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be further understood that the terms “comprises” and/or“comprising” used herein specify the presence of stated features orcomponents, but do not preclude the presence or addition of one or moreother features or components.

It will be understood that when a layer, region, or component isreferred to as being “formed on,” another layer, region, or component,it can be directly or indirectly formed on the other layer, region, orcomponent. For example, intervening layers, regions, or components mayalso be present.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. In other words, since sizes and thicknesses of componentsin the drawings are arbitrarily illustrated for convenience ofexplanation, the embodiments are not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. Expressions such as “atleast one of,” when preceding a list of elements, modify the entire listof elements and do not modify the individual elements of the list.

FIG. 1 illustrates a cross-sectional view of one pixel circuit of athin-film transistor array substrate included in an organiclight-emitting display apparatus according to an embodiment.

The thin-film transistor array substrate includes at least one thin-filmtransistor. The thin-film transistor array substrate may include aplurality of regularly arranged thin-film transistors TFT, a pluralityof irregularly arranged thin-film transistors TFT, or one thin-filmtransistor TFT.

As shown in FIG. 1, the one pixel circuit may include a substrate 110, athin-film transistor TFT on the substrate 110, and a planarization layerPL on the thin-film transistor TFT.

Referring to FIG. 1, a buffer layer 111 may be formed on the substrate110. The buffer layer 111 may act as a barrier layer and/or a blockinglayer for preventing the spread of impurity ions, preventing theinfiltration of humidity or external air, and for planarizing thesurface of the substrate 110.

A semiconductor layer A of the thin-film transistor TFT is formed on thebuffer layer 111. The semiconductor layer A may include polysilicon andmay include a channel region undoped with impurities, and source anddrain regions doped with the impurities and respectively located at bothsides of the channel region. The impurities may vary depending on a typeof the thin-film transistor TFT, and may be N- or P-type impurities.

A gate insulating layer 120 may be stacked on the entire surface of thesubstrate 110 to cover the semiconductor layer A. The gate insulatinglayer 120 may include an inorganic material, such as, for example,silicon oxide, silicon nitride, or the like, and in a multi-layer or asingle layer. The gate insulating layer 120 insulates between thesemiconductor layer A and a gate electrode G of the thin-film transistorTFT.

A material of the gate electrode G may include one or more of molybdenum(Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag),magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chromium (Cr), lithium (Li), calcium (Ca), titanium (Ti), tungsten (W),or copper (Cu).

An interlayer insulating layer 130 is formed on the entire surface ofthe substrate 110 to cover the gate electrode G.

The interlayer insulating layer 130 may include an inorganic material oran organic material. According to one or more embodiments, theinterlayer insulating layer 130 may include an inorganic material. Forexample, the interlayer insulating layer 130 may include metal oxide ormetal nitride, and the inorganic material may include silicon oxide(SiO₂), silicon nitride (SiN_(x)), silicon oxynitride (SiON), aluminumoxide (Al₂O₃), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), hafniumoxide (HfO₂), zinc oxide (ZnO₂), or the like.

The interlayer insulating layer 130 may include an inorganic material ofsilicon oxide (SiO_(x)) and/or silicon nitride (SiN_(x)), or the likeand in a multi-layer or a single layer. According to one or moreembodiments, the interlayer insulating layer 130 may be formed in adouble structure of SiOx/SiNy or SiNx/SiOy.

The interlayer insulating layer 130 insulates the gate electrode G fromwirings formed on the interlayer insulating layer 130.

A source electrode S and a drain electrode D of the thin-film transistorTFT respectively connected to the source region and the drain regiondoped with the impurities in the semiconductor layer A may be formed onthe interlayer insulating layer 130. In other embodiments, the sourceelectrode S and the drain electrode D may be in the same layer as thesemiconductor layer A. That is, the source electrode S and the drainelectrode D of the thin-film transistor TFT may include polysiliconselectively doped with a doping material.

The planarization layer PL is formed on the entire surface of thesubstrate 110 to cover a plurality of wirings, the source electrode S,and the drain electrode D formed on the interlayer insulating layer 130.A pixel electrode 141 may be formed on the planarization layer PL. Thepixel electrode 141 is connected to the drain electrode D or the sourceelectrode S of the thin-film transistor TFT through a via hole VIA.

The planarization layer PL may include an insulating material. Forexample, the planarization layer PL may include an inorganic material,an organic material, or an organic/inorganic compound, in a single- ormulti-layer structure, and by various deposition methods. According toone or more embodiments, the planarization layer PL may include one ormore materials of polyacrylates resin, epoxy resin, phenolic resin,polyamides resin, polyimides rein, unsaturated polyesters resin, polyphenylenethers resin, poly phenylenesulfides resin, and benzocyclobutene(BCB).

An intermediate layer 143, which includes an organic emission layer, andan opposite electrode 145 may be formed on the pixel electrode 141, andthe pixel electrode 141, the intermediate layer 143, and the oppositeelectrode 145 are components of an organic light-emitting diode (OLED).

The pixel electrode 141 may fill the via hole VIA in the planarizationlayer PL and may be electrically connected to the source electrode S orthe drain electrode D of the thin-film transistor TFT. The pixelelectrode 141 and/or the opposite electrode 145 may be a transparentelectrode or a reflective electrode. For the transparent electrode, thepixel electrode 141 and/or the opposite electrode 145 may include indiumtin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indiumoxide (In₂O₃). For the reflective electrode, the pixel electrode 141and/or the opposite electrode 145 may include a reflective layerincluding Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, a compound thereof, orthe like, and a transparent layer including ITO, IZO, ZnO, or In₂O₃.According to one or more embodiments, the pixel electrode 141 or theopposite electrode 145 may have an ITO/Ag/ITO structure.

As described above, the pixel electrode 141, the intermediate layer 143,and the opposite electrode 145 form the OLED. Holes and electronsinjected from the pixel electrode 141 and the opposite electrode 145 ofthe OLED may be combined in the organic emission layer of theintermediate layer 143, thereby emitting light.

The intermediate layer 143 may include an organic emission layer. Asanother example, the intermediate layer 143 may include the organicemission layer and may further include at least one of a hole injectionlayer (HIL), a hole transport layer (HTL), an electron transport layer(ETL), and an electron injection layer (EIL). In other embodiments, theintermediate layer 143 may include the organic emission layer and mayfurther include other various function layers. The opposite electrode145 is formed on the intermediate layer 143. The opposite electrode 145forms an electric field together with the pixel electrode 141 so thatthe intermediate layer 143 emits light. The pixel electrode 141 may bepatterned for each pixel, and the opposite electrode 145 may be formedover all pixels such that a common voltage is applied to all the pixels.

Each of the pixel electrode 141 and the opposite electrode 145 may be atransparent electrode or a reflective electrode. The pixel electrode 141may function as an anode electrode, and the opposite electrode 145 mayfunction as a cathode electrode. In other embodiments, the pixelelectrode 141 may function as a cathode electrode, and the oppositeelectrode 145 may function as an anode electrode.

Although only one OLED is shown in FIG. 1, a display panel may include aplurality of OLEDs. One pixel may be formed for each OLED, and a red,green, blue, or white color may be realized for each pixel, as anexample.

In other embodiments, the intermediate layer 143 may be commonly formedfor the whole pixel electrodes 141 regardless of a position of eachpixel. In this case, the organic emission layer may be formed such thatlayers respectively including emission materials emitting red, green,and blue lights are vertically stacked or are mixed. Alternatively,other colors may be combined if white light is emitted. In addition, acolor conversion layer or a color filter for converting the emittedwhite light into a predetermined color may be further included.

In addition, the organic light-emitting display apparatus may furtherinclude a pixel-defining spacer HPDL on the planarization layer PL.

The pixel-defining spacer HPDL in one embodiment indicates a componentwhich performs both the role of a pixel-defining layer for defining apixel area and a non-pixel area, and the role of a spacer formaintaining a gap between the substrate 110 and a sealing substrate (notshown).

Therefore, the organic light-emitting display apparatus according toembodiments herein includes the pixel-defining spacer HPDL capable ofperforming both roles, and thus time and costs are saved in terms of aprocess.

The pixel-defining spacer HPDL may include an opening through which thepixel electrode 141 is exposed and may be formed to cover all over thesubstrate 110. As shown in FIG. 1, the intermediate layer 143 may beformed in the opening such that the opening substantially becomes apixel area.

The pixel-defining spacer HPDL may be disposed between pixel areas todefine a pixel area and a non-pixel area, and may protrude towards thetop as shown in FIG. 1. Since the pixel-defining spacer HPDL performsboth the role of a pixel-defining layer and the role of a spacer, thepixel-defining spacer HPDL may protrude towards the top to have asufficient height. Accordingly, the pixel-defining spacer HPDL maymaintain the gap between the substrate 110 and the sealing substrate(not shown) on the substrate 110, and may also prevent a decrease in adisplay characteristic due to an external shock.

Although FIG. 1 shows a shape of the pixel-defining spacer HPDLaccording to one embodiment, the shape of the pixel-defining spacer HPDLis not limited thereto, and any shape may be applied thereto if theshape sufficiently performs both the role of a pixel-defining layer andthe role of a spacer.

The pixel-defining spacer HPDL may be formed by stacking an insulatingmaterial which may include an organic material or an inorganic material.The organic material may include one of BCB, an acrylic photoresist, aphenolic photoresist, a polyimides photoresist, or other photosensitiveresins. However, embodiments are not limited thereto.

FIG. 2 illustrates a top view of an organic light-emitting displayapparatus according to an embodiment. FIG. 2 shows only a plurality ofcolor pixels R, G, and B and pixel-defining spacers HPDL for convenienceof description.

As shown in FIG. 2, in one example, each pixel-defining spacer HPDL maybe formed between two neighboring blue pixels B.

When it is defined, as in FIG. 2, that a vertical direction is a firstdirection and a horizontal direction that is perpendicular to the firstdirection is a second direction, each pixel-defining spacer HPDL may beformed between two blue pixels B neighboring in the first direction.

A thin-film transistor array substrate may be formed such that bluepixels B in a pixel area have different gaps therebetween, while gapsbetween red pixels R and green pixels G remain constant.

That is, unlike the arrangement of the red pixels R and the green pixelsG with a constant gap therebetween, the blue pixels B may be regularlyarranged such that gaps between two neighboring blue pixels B maintaintwo gaps, W and N.

Referring to FIG. 2, the blue pixels B may be alternately arranged suchthat gaps between two neighboring blue pixels B maintain a relativelywide gap W, and a relatively narrow gap N.

In this case, as described above, the pixel-defining spacer HPDL may beformed between two neighboring blue pixels B. The pixel-defining spacerHPDL may be formed between two blue pixels B maintaining the relativelywide gap W therebetween.

Commonly, in the existing organic light-emitting display apparatus, aspacer is formed between a red pixel R and a green pixel G. However, inthis case, since a gap between the spacer and each pixel cannot besufficiently secured, a dark spot may be generated due to a stabbingeffect.

Accordingly, in the organic light-emitting display apparatus accordingto embodiments herein described, the pixel-defining spacer HPDL isformed between two neighboring blue pixels B located to sufficientlysecure a gap therebetween to solve the dark spot problem.

The relatively wide gap W of the gaps between two neighboring bluepixels B may be about 67.5 μm, and the relatively narrow gap N may beabout 12.5 μm. The gap between neighboring red and green pixels R and Gmay be about 27.5 μm.

Of course, the above-described numeric values of the gaps between thepixels R, G, and B are only illustrative, and embodiments are notlimited thereto.

By forming the pixel-defining spacer HPDL between two blue pixels Bhaving a maximum gap W therebetween, a space is well used, and bymaximizing a distance between the pixel-defining spacer HPDL and anopening region, a damage of a pixel due to an external shock may beprevented when a partial shock is applied.

Referring to FIG. 2, in one embodiment of the organic light-emittingdisplay apparatus, the pixel-defining spacer HPDL may be formed betweentwo neighboring blue pixels B such that a region between a green pixel Gand a red pixel R, and a region between another green pixel G andanother red pixel R are respectively located to the left and right ofthe pixel-defining spacer HPDL.

The pixel-defining spacer HPDL may be formed between two neighboringgreen pixels G and between two neighboring red pixels R in the seconddirection that is perpendicular to the first direction. In particular,the pixel-defining spacer HPDL may be formed in a space betweenneighboring green pixels G and red pixels R.

The pixel-defining spacer HPDL may be formed between blue pixels Bspaced apart by the gap W which is relatively wide with respect to gapsbetween blue pixels B adjacent to one another in the first directionthat is the vertical direction in FIG. 2. The pixel-defining spacer HPDLmay be formed at the same location as a location between neighboring redand green pixels R and G. In addition, the pixel-defining spacer HPDLmay be formed in a region between two neighboring green pixels G andbetween two neighboring red pixels R in the second direction that isperpendicular to the first direction.

Therefore, the pixel-defining spacer HPDL may be located in a vacantspace around pixels R, G, and B without pixels R, G, and B in the leftand right regions of the pixel-defining spacer HPDL in the seconddirection.

Accordingly, a predetermined gap is maintained in the vertical directionof the pixel-defining spacer HPDL, and a vacant space without pixels isformed to the left and right of the pixel-defining spacer HPDL, andthus, even if the pixel-defining spacer HPDL moves due to an externalshock, the pixel-defining spacer HPDL does not move to an openingregion, and accordingly, a deposited object may be prevented from beingstabbed.

As shown in FIG. 2, the pixel-defining spacer HPDL may be formed in arectangular shape, but is not limited thereto.

In addition, distances from the pixel-defining spacer HPDL to a bluepixel B, to a red pixel R, and to a green pixel G may be variouslyadjusted.

As described above, compared with the existing thin-film transistorarray substrate, distances from the pixel-defining spacer HPDL to nearbypixels may be maximized, and thus a slip distance of the pixel-definingspacer HPDL may be secured to thereby prevent a partial shock, and evenwhen the pixel-defining spacer HPDL moves, the pixel-defining spacerHPDL does not move to an opening region, and thus a deposited object maybe prevented from being stabbed.

FIG. 3 illustrates a top view of a thin-film transistor array substrateaccording to another embodiment. In FIG. 3, like reference numerals inFIGS. 1 and 2 refer to like elements, and the description thereof is notrepeated for conciseness of the description.

In one embodiment of an organic light-emitting display apparatus, thepixel-defining spacer HPDL may be formed in a lozenge shape.Accordingly, the pixel-defining spacer HPDL may be formed by maximallyusing a vacant space between pixels while maintaining a minimum distanceto a pixel as a predetermined gap.

As shown in FIG. 3, when the pixel-defining spacer HPDL is formed in alozenge shape, a vacant space between pixels may be maximally used, andthus a size of the pixel-defining spacer HPDL may be relatively large.

By forming the pixel-defining spacer HPDL in a lozenge shape on thethin-film transistor array substrate, a minimum distance to blue pixelsB in the vertical direction may be maintained as about 8 μm, and aminimum distance to red and green pixels R and G in the horizontaldirection may be maintained as about 9.6 μm.

The above-described numeric values as the distances to the blue, red,and green pixels B, R, and G are only illustrative, and embodiments arenot limited thereto. In addition, the numeric values may be variouslyadjusted if the pixel-defining spacer HPDL is formed at the locationdescribed above.

FIG. 4 illustrates a top view of an organic light-emitting displayapparatus according to another embodiment. In FIG. 4, like referencenumerals in FIGS. 1 and 2 refer to like elements, and the descriptionthereof is not repeated for conciseness of the description.

As shown in FIG. 4, in the organic light-emitting display apparatus, thepixel-defining spacer HPDL may be formed in a hexagonal shape.

By forming the pixel-defining spacer HPDL in a hexagonal shape, a vacantspace between pixels may be maximally used while maintaining a distanceto a pixel as a predetermined gap, and thus a size of the pixel-definingspacer HPDL may be relatively large.

By forming the pixel-defining spacer HPDL in a hexagonal shape in theorganic light-emitting display apparatus, a minimum distance to bluepixels B in the vertical direction may be maintained as about 9 μm, anda minimum distance to red and green pixels R and G in the horizontaldirection may be maintained as about 9.6 μm.

The above-described numeric values as the distances to the blue, red,and green pixels B, R, and G are only illustrative, and embodiments arenot limited thereto. In addition, the numeric values may be variouslyadjusted if the pixel-defining spacer HPDL is formed at the locationdescribed above.

FIG. 5 illustrates a top view of an organic light-emitting displayapparatus according to another embodiment. In FIG. 5, like referencenumerals in FIGS. 1 and 2 refer to like elements, and the descriptionthereof is not repeated for conciseness of the description.

Unlike the pixel-defining spacers HPDL described above, a thin-filmtransistor array substrate according to one embodiment may includepixel-defining spacers HPDL having different shapes.

As shown in FIG. 5, the thin-film transistor array substrate may includepixel-defining spacers HPDL having two shapes in consideration of gapsbetween red, green, and blue pixels R, G, and B.

As described above, gaps between two neighboring blue pixels B maintainthe relatively wide gap W and the relatively narrow gap N. In this case,pixel-defining spacers HPDL of a quadrilateral shape may be formedbetween two blue pixels B maintaining the relatively wide gap W, andpixel-defining spacers HPDL of a trapezoidal shape may be formed betweentwo blue pixels B maintaining the relatively narrow gap N.

Accordingly, sizes and the number of pixel-defining spacers HPDL may bemaximally formed while maintaining a maximum distance between thepixel-defining spacers HPDL and neighboring pixels.

The pixel-defining spacers HPDL formed between two neighboring bluepixels B maintaining the relatively narrow gap N may be formed in atrapezoidal shape, and as shown in FIG. 5, the pixel-defining spacersHPDL may be formed such that the topside “s” that is a short side islocated between two blue pixels B and the bottom side “l” that is a longside is located between a green pixel G and a red pixel R.

The pixel-defining spacers HPDL are formed by considering that a gapbetween two blue pixels B is relatively narrow, whereas a gap between agreen pixel G and a red pixel R is relatively wide.

The pixel-defining spacers HPDL may be formed in a trapezoidal shapesuch that the topside s that is a short side of each pixel-definingspacer HPDL is located between two blue pixels B to maximally maintain agap between the pixel-defining spacers HPDL and the two blue pixels Band the bottom side 1 that is a long side of each pixel-defining spacerHPDL is located between a green pixel G and a red pixel R.

The pixel-defining spacer HPDL may be formed of a trapezoidal shape evenbetween two blue pixels B maintaining the relatively narrow gap N inconsideration of a location where the pixel-defining spacer HPDL movesvertically or horizontally while maximally using gaps between red,green, and blue pixels R, G, and B.

Referring to FIG. 5, a pixel-defining spacer HPDL of a quadrilateralshape may be formed between two blue pixels B maintaining the relativelywide gap W. The quadrilateral shape of the pixel-defining spacer HPDL isnot limited, and any quadrilateral shape may be applied.

In addition, as shown in FIG. 5, the pixel-defining spacer HPDL may bedivided into two pixel-defining spacers HPDL of a quadrilateral shape.

Accordingly, on the thin-film transistor array substrate, a size of eachpixel-defining spacer HPDL may be maximally formed within a range ofmaintaining a gap, and the number of pixel-defining spacers HPDL mayalso be maximized.

As described above, according to the one or more embodiments, by forminga pixel-defining spacer using a space between pixels, a deposited objectstabbing problem and a partial shock problem may be prevented.

It should be understood that the embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While certain embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. An organic light-emitting display apparatuscomprising: a thin-film transistor on a substrate; a planarization layeron the thin-film transistor; and a pixel-defining spacer on theplanarization layer, wherein the pixel-defining spacer defines a pixelarea and is between two pixels adjacent in a first direction.
 2. Theorganic light-emitting display apparatus of claim 1, wherein the twoadjacent pixels are blue.
 3. The organic light-emitting displayapparatus of claim 2, wherein among the blue pixels in the pixel area, afirst gap between first two neighboring blue pixels and a second gapbetween second two neighboring blue pixels are alternately and regularlyformed, wherein the first gap is different from the second gap, andwherein the pixel-defining spacer is formed in a region in which a gapbetween two neighboring blue pixels is wide.
 4. The organiclight-emitting display apparatus of claim 2, wherein the pixel-definingspacer is between two green pixels adjacent in a second direction andbetween two red pixels adjacent in the second direction, wherein thesecond direction is perpendicular to the first direction.
 5. The organiclight-emitting display apparatus of claim 1, wherein the pixel-definingspacer is rectangular shaped.
 6. The organic light-emitting displayapparatus of claim 1, wherein the pixel-defining spacer is lozengeshaped.
 7. The organic light-emitting display apparatus of claim 6,wherein the pixel-defining spacer is spaced apart from the blue pixelsby at least about 8 μm.
 8. The organic light-emitting display apparatusof claim 6, wherein the pixel-defining spacer is spaced apart from greenpixels or red pixels by at least about 9.2 μm.
 9. The organiclight-emitting display apparatus of claim 1, wherein the pixel-definingspacer is hexagonal shaped.
 10. The organic light-emitting displayapparatus of claim 9, wherein the pixel-defining spacer is spaced apartfrom the blue pixels by at least about 9 μm.
 11. The organiclight-emitting display apparatus of claim 9, wherein the pixel-definingspacer is spaced apart from green pixels or red pixels by at least about9.6 μm.
 12. The organic light-emitting display apparatus of claim 2,wherein blue pixels in the pixel area are formed such that two differentgaps, each gap between two neighboring blue pixels, are alternately andregularly formed, and the pixel-defining spacer is formed in differentshapes in a region in which a gap between a first two neighboring bluepixels is narrow and in a region in which a gap between a second twoneighboring blue pixels is wide.
 13. The organic light-emitting displayapparatus of claim 12, wherein the pixel-defining spacer is trapezoidalshaped in the region in which a gap between two neighboring blue pixelsis narrow.
 14. The organic light-emitting display apparatus of claim 13,wherein the top of the trapezoidal shaped pixel-defining spacer islocated between the two blue pixels, and the bottom of the trapezoidalshaped pixel-defining spacer is located between adjacent green and redpixels.
 15. The organic light-emitting display apparatus of claim 12,wherein the pixel-defining spacer is quadrilateral shaped in the regionin which a gap between two neighboring blue pixels is wide.